1. Field
The following description relates to a method of producing graphene, a method of producing reduced graphene oxide using a surfactant containing an aromatic functional group, and reduced graphene oxide and nanostructures produced by such methods.
2. Description of Related Art
Graphene has attracted great interest in the scientific community for its typical physical properties and potential applicability in the fields of nanoelectronics, energy storage materials, polymer composition materials, and sensing technologies. Among the techniques that have been developed to produce high-quality graphene sheets in large numbers, mechanical exfoliation has been principally used to produce pure graphene sheets for basic science researches. However, the technique of mechanical exfoliation is not suitable for the mass production of graphene.
Accordingly, developing an alternative production method, which enables large-scale synthesis of graphene sheets, still remains a challenge. In addition, the hydrophobicity of graphene nanosheets and the tendency of graphene nanosheets to be agglomerated within a solvent are some of the factors hindering the development of an alternative graphene production method, restricting the potential versatile applicability of graphene. Recently, it has been reported that a large number of graphene sheets can be produced by reducing exfoliated graphene oxide. Also, it has been reported that since the graphene sheet can be stabilized by an amphiphilic polymer and a monomer surfactant, a stable graphene-dispersed solution is formed under the presence of such a surfactant. However, since it is very difficult to remove the surfactant from the dispersed solution after the formation of the stable graphene-dispersed solution under the presence of the surfactant, it is generally not desirable to use a surfactant in the production of graphene. A conventional functionalized graphene sheet has been produced by thermal expansion of graphene oxide without using a surfactant, and a stable dispersed solution of graphene chemically modified by alkylamine has also been reported. However, the former thermal method has a restriction in terms of a solution process, and the latter amine doping method has a restriction in terms of its application due to the purity of graphene.
Accordingly, in functionalization of the graphene sheet for application to devices, improving the dispersibility and the self-assembly characteristics of the graphene nanosheet has been the key issues. However, despite the fact that aromatic organic molecules are reagents commonly used in the organic chemistry, there has been no report on non-shared functionalization of the graphene sheet through π-π interaction using aromatic organic molecules. Also, there has been no report on removing a surfactant after the use thereof, in surface attachment or processing of graphene.
In this regard, Korean Patent Application Publication No. 10-2013-0011099 describes a graphene-dispersed solution and a producing method thereof, but still has the foregoing drawbacks.